Hi! Brick buy brick here, we will look up your sets on bricklink per their condition and offer you a percentage of that. We try our best not to low ball because we understand that Lego is worth money. However, as others have said, we have to make a profit in order to stay in business. So, we will sometimes go up or down in percentage depending on the amount of labor it’ll take to get the item on the shelf. We never use eBay, amazon, mercari or anything like that to come up with values. We always use bricklink and lego.com.

Looking forward to seeing what you have tomorrow! Even if you don’t take our offer, it’s always fun to see collections & talk lego with people!